docs: def help():
      """List all targets"""
      print("Please use '{} <target>' where <target> is one of"
            .format(sys.argv[0]))
      width = max(len(name) for name in TARGETS)
      for name, target in TARGETS.items():
          print('  {name:{width}} {descr}'.format(name=name, width=width,
                                                  descr=target.__doc__))